Mutant genes found for asthma, point to possible therapy

HONG KONG (Reuters) - A drug used to treat rheumatoid arthritis could help asthma patients, scientists said on Friday, as they identified two mutant genes that may predispose a person to asthma.

Over 235 million people worldwide suffer from asthma and it is the most common chronic disease among children, according to the World Health Organization.

In a paper published in The Lancet medical journal, researchers in Australia said they had identified the two rogue genes after comparing 58,000 DNA samples of people living in Australia, Europe and the United States with and without asthma.

"We found two regions of the DNA that are consistently different between asthmatics and non-asthmatics," lead author Manuel Ferreira at the Queensland Institute of Medical Research in Brisbane told Reuters by telephone.

One of the genes is also known to be linked to rheumatoid arthritis (RA) and the researchers suggested that the drug tocilizumab, which is used to treat RA, may also work for asthma.

Tocilizumab, marketed under the brand Actemra by Roche Holding AG, targets a certain molecule in the body called "interleukin-6 receptor" and reduces inflammation in RA patients.

"Targeting interleukin-6 receptor may be a good strategy to reduce or prevent inflammation (in asthma) in the same way that it is used to prevent or reduce inflammation in rheumatoid arthritis," Ferreira said, adding that more research should be carried out to confirm if the drug may help asthma patients.

Asthma is a chronic inflammatory disease in which the airways in the lungs become inflated, narrowed and obstructed, causing breathing difficulty.

Apart from genetic reasons, other risk factors for asthma are inhaled substances that may provoke allergic reactions or irritate the airways, such as tobacco smoke, chemical irritants in the workplace and polluted air.